1. Field of the Invention
The present invention relates to a rotary cutter for a mower used for mowing grass and the like with a cord (principally made of nylon) extending in a radial direction of a case which is rotationally-driven by power of a motor or the like by way of an axis of rotation, and in particular to a rotary cutter of a type in which winding a cord around a reel is performed without removing a case and a cover, wherein even if the cord wound around the reel is consumed and shortened due to wear of the cord, the cutting work can be continued by preventing the remaining cord wound around the reel from falling out of the reel.
2. Description of the Related Art
As this type of rotary cutter, it is conventionally known a rotary cutter having a reel which houses a nylon cord, wherein when the cord is worn away, the cord is let out from the reel by pressing the cutter on the ground during rotation, by tapping the cutter or by running up the rotation of the cutter. As to this type of rotary cutter, when the cord housed in the reel was worn out, it was common to take out the reel by disassembling the rotary cutter, and wind a new cord, and then rearranging its components again. However, by such a way, it is very troublesome and inconvenient to carry out such procedures during mowing. Moreover, when the rotary cutter is disassembled and the reel is taken out, it has been feared that these components may be lost since associated components of the reel and other components are taken out at the same time. On this account, as the rotary cutter in which a cord replacement can be simplified when the cord is worn away, or, the rotary cutter in which the cord is replaceable without disassembling the rotary cutter itself, for example, a rotary cutter in which through-holes are formed in a part of a cylindrical body (a cord-winding part) of a reel, and the cord is inserted through the through-holes and wound onto the cylindrical body of the reel (see Japanese Utility Model Registration No. 2509199 (Unexamined Utility Model Specification 03-112218) and Japanese Patent Application Laid-Open No. 2005-124501), and a rotary cutter of in which with a cutter head portion thereof attached to a rotary driving shaft without removing a case and a cover, a cord is inserted through cord guides on both sides, and the cord is wound around a reel by rotating a pressing body (generally called “button”) that rotates the reel integrally (see US 2009/0223065 A1), or the like, is suggested.
However, in the case of the conventional rotary cutter as claimed in Japanese Utility Model Registration No. 2509199 and Japanese Patent Application Laid-Open No. 2005-124501, there is an advantage that the cord is replaceable without disassembling the rotary cutter and taking out the reel. However, for example, in the case of a rotary cutter described in Japanese Utility Model Registration No. 2509199, there are some disadvantages that it is necessary to provide a cord through-hole formed between an outer circumferential surface and an inner circumferential surface of a cylindrical body of a reel (a cord-winding part) of a reel, the cord through-hole being perpendicular to an axis of rotation without providing on the inner circumferential surface, so that top and bottom positions of its cord insertion opening and a guiding hole can be on the same horizontal plane. As a result, production/processing cannot be easily carried out in order to form its cord through-hole and the guiding hole. Therefore, the production cost of such a rotary cutter can be relatively high. Furthermore, in the cases of the conventional rotary cutters described in Japanese Utility Model Registration No. 2509199 and Japanese Patent Application Laid-Open No. 2005-124501 mentioned above, there is the common disadvantage that it takes a lot of time and trouble to perform a cord insertion/conduction when the cord is wound around the reel. In addition, in the case of the rotary cutter described in US 2009/0223065 A1, as compared with the rotary cutters described in Japanese Utility Model Registration No. 2509199 and Japanese Patent Application Laid-Open No. 2005-124501 mentioned above, a cord replacement work required when the cord is worn is simpler, but there is the disadvantage that when the cord wound around the reel is consumed due to wear of the cord and only a small amount or short length of the cord is left during the cutting work, the remaining cord wound around the reel easily falls out of the reel due to centrifugal force since no means or mechanism to hold the cord is provided and therefore the cutting work cannot be continued.
The present invention has been made to eliminate the disadvantages of the conventional techniques as described above, in particular the disadvantage of the rotary cutter of the type (US 2009/0223065 A1) in which with a cutter head portion thereof attached to a rotary driving shaft without removing a case and a cover, the cord is inserted through cord guides on both sides, and the cord is wound around the reel by rotating a pressing body (generally called button) that rotates the reel integrally, and an object of the present invention is to provide a rotary cutter for a mower not only in which the cord can be wound rapidly and easily, but also in which even when the cord wound around the reel is consumed and shortened due to wear of the cord, the cutting work can be continued by preventing the cord wound around the reel from falling out of the reel.